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Date: Wed, 10 Aug 2005 09:42:45 -0700 (PDT)
From: Don Lewis <truckman@FreeBSD.org>
To: ssouhlal@FreeBSD.org
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Cc: kan@FreeBSD.org, freebsd-current@FreeBSD.org, thierry@herbelot.com
Subject: Re: panic: lock (sleep mutex) vnode interlock not locked
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On 10 Aug, Suleiman Souhlal wrote:
> Hello,
> 
> On Aug 10, 2005, at 12:18 PM, Suleiman Souhlal wrote:
> 
>> Hi,
>>
>> On Aug 10, 2005, at 12:02 PM, Don Lewis wrote:
>>
>>
>>> What is preventing VI_DOOMED from being set while we're waiting for
>>> VOP_LOCK()?  Contrary to what the VOP_LOCK(9) man page says about
>>> LK_INTERLOCK, it looks like lockmgr() drops the vnode interlock  
>>> before
>>> it attempts to grab the vnode lock.
>>>
>>
>> VI_DOOMED is only set by vgonel(), and it requires both the vnode  
>> and the interlock locked.
> 
> I read your message a bit too fast. I think you are right. We should  
> probably move the check for VI_DOOMED etc, after we've acquired the  
> vnode lock.

If you just move the test, you'll probably want to add LK_NOWAIT to the
VOP_LOCK() call to avoid stalling on a vnode that is in use.